1. Field of the Invention
The present invention relates an installation construction method for boiler facilities, and particularly relates to an installation construction method wherein the installation construction schedule can be markedly reduced.
2. Description of the Related Art
FIG. 11 is a schematic configuration diagram of a common boiler facility for electric power production. A boiler main unit 1 is disposed within a boiler building 3 configured of a steel structure 2 around and above, and is suspended from top girders 4 traversing the top of the boiler building 3 by sling bolts.
Secondary air for combustion to the boiler main unit 1 is guided to a furnace combustion chamber with a burner, via a forced draft fan, an air pre-heater 5, a wind box 6, and so on forth. Also, coal fuel transporting air is guided from the air pre-heater 5 to a mill 8 via a primary air duct 7.
Coal to serve as fuel is stored in a bunker 9, and is supplied to the mill 8 while being measured by a stoker 10, and is pulverized to a predetermined particle size. The fine powder coal generated at the mill 8 is supplied to the burner disposed within the wind box 6 through a fuel pipe along with the coal fuel transporting air, and is burned in the furnace combustion chamber.
The hot combustion gas generated by combustion in the furnace combustion chamber is then subjected to heat exchanges within an internal fluid flowing through a secondary superheater 11, a tertiary superheater 12, a reheater 13, a primary superheater 14, an economizer 15, and so on forth, disposed within an air flue of the boiler main unit 1. The combustion gas subjected to heat exchange passes through an economizer discharge gas duct 16, a denitration device, the air pre-heater 5, and an air pre-heater discharge gas duct 17, and is externally discharged from the boiler building 3.
On the other hand, water feed to the boiler main unit 1 is performed by water passing from a condenser outside of the boiler building 3 through a main water pipe to each of the heat exchangers such as the economizer 15, where heat exchange creates high-temperature high-pressure steam, which passes through a main steam pipe and is guided to a high-pressure turbine outside of the boiler building 3.
Steam from a medium-pressure turbine is guided to the reheater 13 via a low-temperature reheating steam pipe, and the reheated steam passes through a high-temperature reheating steam pipe and is guided to a low-pressure turbine outside of the boiler building 3.
FIGS. 12 through 21 are schematic configuration diagrams for describing a conventional boiler facilities installation construction method. In these drawings, FIGS. 13, 15, 17, 19, and 21, are views taken along line A-A in FIGS. 12, 14, 16, 18, and 20, respectively.
As shown in FIGS. 12 and 13, first, a predetermined number of first-level steel columns 21 are erected, and between the first-level steel columns 21 are assembled first floor beams for a floor 22 and second floor beams for a floor 23. Next, as shown in FIGS. 14 and 15, second-level steel columns 24 are erected upon the first-level steel columns 21, and between the second-level steel columns 24 are assembled third floor beams for a floor 25 and fourth floor beams for a floor 26. Next, as shown in FIGS. 16 and 17, third-level steel columns 27 are erected upon the second-level steel columns 24, and between the third-level steel columns 27 are assembled fifth floor beams for a floor 28 and sixth floor beams for a floor 29. Next, as shown in FIGS. 18 and 19, fourth-level steel columns 30 are erected upon the third-level steel columns 27, and between the fourth-level steel columns 30 are assembled seventh floor beams for a floor 31, eighth floor beams for a floor 32, and top girders 33, thereby completing construction of the boiler building 34.
Subsequently, as shown in FIGS. 20 and 21, the top girders 33 are used to suspend the boiler main unit 35 from the top of the boiler building 34. Also, ducts 36, a bunker 37, stoker 38, fuel pipes 39, soot blower 40, various types of piping, cable tray 41, railing, electric panel, and so on forth, are carried into the boiler building 34 from the sides, by crane, temporary monorail, chain hoist, and so on forth, and positioned and welded into place, thereby completing installation of the boiler facilities.
Thus, with the conventional boiler facility installation construction method, the series of work from manufacturing the steel beams to installation on-site to construct the boiler building has been performed by a steel fabrication manufacturer. The ducts, bunker, stoker, fuel pipes, soot blower, various types of piping, cable tray, railing, electric panel, and so on forth, to be installed in the boiler building have been carried in and installed following completion of the boiler building.
This means that the work of carrying in and installing various types of equipment and accessories is concentrated in the period following completion of the boiler building, leading to problems in that all work regarding ducts, piping, and so on forth, is high-place work, meaning deterioration in work capability, and in that work within a limited space means work is restricted, requiring a longer construction schedule, and further that the amount of high-risk work at high places is great, leading to higher construction costs, and increased risk of workplace accidents.
Also, with arrangements wherein multiple members are combined to form a unit, and these are hoisted above the installation location using a crane and the lower for installation, already-assembled beams, columns, various types of equipment, accessory members, and the like, tend to interfere with carrying in and installing the units.
In order to solve the above problems, the present Inventors have previously studied a boiler facility installation method such as illustrated in FIGS. 22 through 31. In these drawings, FIGS. 23, 25, 27, 29, and 31, are views taken along line A-A in FIGS. 22, 24, 26, 28, and 30, respectively.
First, as shown in FIGS. 22 and 23, a predetermined number of first-level steel columns 21 are assembled, and in conjunction therewith, a first floor unit 45 is disposed between the first-level steel columns 21. A floor unit has at least floor beams and a floor, and has been assembled beforehand, taking the hoisting limit load of the crane into consideration.
A duct block 47, fuel pipe block 48, cable tray 49, mill, and so on forth, are carried in above the first floor unit 45, and installed. A second floor unit 50 is assembled above the first floor unit 45, with a duct block 47 and stoker 51 being carried in and attached.
Next, as shown in FIGS. 24 and 25, second-level steel columns 24 are erected, with a third floor unit 52 and fourth floor unit 53 being disposed between the second-level steel columns 24, and also a bunker cone block 57, piping 55, soot blower 56, and so on forth, being carried in and installed.
Next, as shown in FIGS. 26 and 27, third-level steel columns 27 are erected, with a fifth floor unit 58 being disposed between the third-level steel columns 27, and also piping 55, soot blower 56, and so on forth, being carried in and installed.
A sixth floor unit 59 is assembled above the fifth floor unit 58, with a piping skid and bunker cylinder block 60 and the like being carried in and installed. The piping skid is configured of integrally linking at least piping and valves.
Next, as shown in FIGS. 28 and 29, fourth-level steel columns 30 are erected, and following piping 55 and the like being carried in and installed, a seventh floor unit 61 and eighth floor unit 62 are disposed between the fourth-level steel columns 30, and also top girders 33 and the like are carried in and installed.
As shown in FIGS. 30 and 31, the boiler main unit 35 is carried in from a rear opening portion 64 of the boiler building 34, the boiler main unit 35 is lifted up to a predetermined height using crane, winches or jacks, and is suspended from the top girders 33 by sling bolts. Other equipment and accessories and the like which could not be carried in parallel to construction of the boiler building 34 can be carried in and installed following completion of the construction of the boiler building 34.
According to this installation method, a great part of the various types of equipment and accessory members to be installed within the boiler building can be assembled near the ground rather than at high places, and can be directly assembled by crane as with the steel structure, so work safety can be improved, and construction costs can be reduced due to standardization of work amount during the construction schedule and improved work efficiency.
Boiler facility installation construction methods are described in, for example, Japanese Unexamined Patent Application Publication No. 07-091603, Japanese Unexamined Patent Application Publication No. 08-114302, Japanese Unexamined Patent Application Publication No. 08-261405, Japanese Unexamined Patent Application Publication No. 11-211003, Japanese Unexamined Patent Application Publication No. 2002-098304, and Japanese Unexamined Patent Application Publication No. 2002-213707.
However, the boiler facility installation construction method illustrated in FIGS. 22 through 31 is not trouble-free, either. FIG. 32 is a schematic plan view illustrating each of the zones of the boiler facilities. As shown in the drawing, the boiler facilities can be generally divided into a first zone 65 extending from the front of the boiler facilities to either side thereof, a second zone 66 which is the back side of the boiler facilities, and a third zone 67 which is the inner side surrounded by the first zone 65 and the second zone 66.
With the above-described earlier-studied boiler facility installation construction method, beams for suspending the boiler main unit are installed at the top of the boiler building following completion of the first zone 65, the boiler main unit is carried into the third zone 67 from the second zone 66, where it is suspended from the beams, and subsequently thermal insulation and the like is installed where necessary.
Accordingly, the construction schedule for the boiler facilities can be generally classified into a steel structure construction/facilities installation period, a boiler main unit installation period, and a thermal insulation installation period, with a certain construction period allocated for each. As one example, for a commercial-use 700 megawatt class coal fuel boiler facility, there has been the need to allow 7 months, 9 months, and 8 months, respectively, for these three periods, meaning that a total of 24 months is required.
However, as of recent, there is great demand for reduction in the construction schedule from the perspective of cash flow and from the perspective of early electric power selling from starting operations early, and this demand cannot be met. A particularly troublesome factor is how large the units can be manufactured and transported to the site. For example, in the event that the location for installation is extremely easily accessible, such as on the waterfront accessible by large work barges, giant-sized units could be floated in and installed. However, this is not always the case, and road width may mandate the size of the units. Not being able to transport giant-sized units to the site is a particular problem.